中文摘要：

目的：观察κ阿片受体激动剂U 50 488H对自发性高血压大鼠（SHR）的利尿作用并探讨其作用机制。方法：用整体实验观察U 50 488H对WKY鼠和SHR血压和尿量的影响；应用放射免疫分析方法观察WKY鼠和SHR血浆中体液因子的变化。结果：U 50 488H显著降低WKY鼠和SHR的血压，对SHR产生的降压效应大于WKY鼠；U 50 488H剂量依赖性地引起WKY鼠和SHR尿量的增加，而且对SHR的利尿作用强于WKY鼠；测定血浆因子水平发现，U 50 488H不仅能引起WKY鼠和SHR血浆ADH水平的显著下降，并且对SHR血浆ADH水平的降低效应大于WKY鼠；另外，U 50 488H对WKY鼠血浆AngⅡ水平无明显影响，但可以引起SHR血浆AngⅡ水平显著下降。U 50 488H的以上效应均可被选择性κ阿片受体阻断剂nor—BNI所阻断。结论：κ阿片受体激动剂U 50 488H显著下调血浆中抗利尿激素和血管紧张素Ⅱ的水平可能与其引起SHR强利尿效应有关。

英文摘要：

AIM ： To investigate the diuretic effects of U 50 488 H, a selective κ - opioid receptor agonist, in spontaneously hypertensive rats （SHR） and explore their mechanism. METHODS： The physiological experimental technique was used to measure the blood pressure （ BP）, and the volume of urine output in normatensive WKY （ Wistar - Kyoto） rats and SHR was measured. The plasma levels of some humoral factors were detected by radioimmunoassay. RESULTS： U 50 488H decreased BP significantly in WKY rats and SHR, and the decrease of BP in SHR was more than that in WKY rats. U 50 488H increased the urine volume dose - dependently in WKY rats and SHR. The urine volume of SHR increased by U 50 488H was more than that of WKY rats. U 50 488H （ 1 mg/kg） produced marked decrease in plasma concentration of ADH in WKY rats and SHR, and the decrease in SHR was significantly stronger than that in WKY. U 50 488H also induced a decrease in plasma concentration of Ang Ⅱ in SHR, while it had no influence on the plasma concentration of Ang Ⅱ in WKY rats. These effects of U 50 488H were abolished by nor - BNI, a selective κ - opioid receptor antagonist. CONCLUSION： The significant decreases in plasma concentration of ADH and Ang Ⅱ may be responsible for the effective diuresis of κ - opioid receptor stimulation by U 50 488H in SHR.